Detecting structural changes in viral capsids by hydrogen exchange and mass spectrometry
Detecting structural changes in viral capsids by hydrogen exchange and mass spectrometry
复制标题
DOI：
10.1110/ps.100101
复制
发表时间：
2001-06-01
期刊：
影响因子：
8
通讯作者：
Smith, DL
中科院分区：
文献类型：
--
作者：
Wang, LT;Lane, LC;Smith, DL
用酰胺氢交换和质谱仪研究了pH诱导的雀麦花叶病毒(BMV)衣壳结构的变化。通过在pH为5.4和7.3的D2O中孵育完整的病毒颗粒，以结构敏感的方式标记衣壳蛋白。用质谱仪测定完整的外壳蛋白及其蛋白降解片段中的氚含量。由构造变动引起的最大氚增量出现在位于不对称单元中心的准三重轴周围区域。氚水平的增加表明这些区域的结构正在松动。这一观察结果证实了先前提出的BMV和豌豆褪绿斑驳病毒(CCMV)的肿胀模型，并与最近通过冷冻电子显微镜和图像重建确定的肿胀CCMV的结构一致。还检测到延长的N-末端和C-末端臂的结构变化，并与其他肿胀植物病毒的结果进行了比较。这项研究表明，蛋白质碎片/酰胺氢交换是探测病毒衣壳结构变化的有用工具。
Amide hydrogen exchange and mass spectrometry have been used to study the pH-induced structural changes in the capsid of brome mosaic virus (BMV). Capsid protein was labeled in a structurally sensitive way by incubating intact viral particles in D2O at pH 5.4 and 7.3. Deuterium levels in the intact coat protein and its proteolytic fragments were determined by mass spectrometry. The largest deuterium increases induced by structural alteration occurred in the regions around the quasi-threefold axes, which are located at the center of the asymmetric unit. The increased levels of deuterium indicate loosening of structure in these regions. This observation confirms the previously proposed swelling model for BMV and cowpea chlorotic mottle virus (CCMV) and is consistent with the structure of swollen CCMV recently determined by cryo-electron microscopy and image reconstruction. Structural changes in the extended N- and C-terminal arms were also detected and compared with the results obtained with other swollen plant viruses. This study demonstrates that protein fragmentation/amide hydrogen exchange is a useful tool for probing structural changes in viral capsids.